Rollup of 16 pull requests

.mailmap

@@ -52,6 +52,7 @@ Chris C Cerami <[email protected]> Chris C Cerami <chrisccer
 Chris Pressey <[email protected]>
 Chris Thorn <[email protected]> Chris Thorn <[email protected]>
 Chris Vittal <[email protected]> Christopher Vittal <[email protected]>
+Christian Poveda <[email protected]> <[email protected]> <[email protected]>
 Clark Gaebel <[email protected]> <[email protected]>
 Clinton Ryan <[email protected]>
 Corey Richardson <[email protected]> Elaine "See More" Nemo <[email protected]>

src/bootstrap/bin/rustc.rs

@@ -291,15 +291,6 @@ fn main() {
         cmd.arg("-Z").arg("verify-llvm-ir");
     }
 
-    let color = match env::var("RUSTC_COLOR") {
-        Ok(s) => usize::from_str(&s).expect("RUSTC_COLOR should be an integer"),
-        Err(_) => 0,
-    };
-
-    if color != 0 {
-        cmd.arg("--color=always");
-    }
-
     if env::var_os("RUSTC_DENY_WARNINGS").is_some() && env::var_os("RUSTC_EXTERNAL_TOOL").is_none()
     {
         cmd.arg("-Dwarnings");

src/bootstrap/compile.rs

@@ -29,7 +29,7 @@ use build_helper::{output, mtime, up_to_date};
 use filetime::FileTime;
 use serde_json;
 
-use util::{exe, libdir, is_dylib, CiEnv};
+use util::{exe, libdir, is_dylib};
 use {Compiler, Mode, GitRepo};
 use native;
 
@@ -1034,29 +1034,6 @@ pub fn add_to_sysroot(builder: &Builder, sysroot_dst: &Path, stamp: &Path) {
     }
 }
 
-// Avoiding a dependency on winapi to keep compile times down
-#[cfg(unix)]
-fn stderr_isatty() -> bool {
-    use libc;
-    unsafe { libc::isatty(libc::STDERR_FILENO) != 0 }
-}
-#[cfg(windows)]
-fn stderr_isatty() -> bool {
-    type DWORD = u32;
-    type BOOL = i32;
-    type HANDLE = *mut u8;
-    const STD_ERROR_HANDLE: DWORD = -12i32 as DWORD;
-    extern "system" {
-        fn GetStdHandle(which: DWORD) -> HANDLE;
-        fn GetConsoleMode(hConsoleHandle: HANDLE, lpMode: *mut DWORD) -> BOOL;
-    }
-    unsafe {
-        let handle = GetStdHandle(STD_ERROR_HANDLE);
-        let mut out = 0;
-        GetConsoleMode(handle, &mut out) != 0
-    }
-}
-
 pub fn run_cargo(builder: &Builder,
                  cargo: &mut Command,
                  tail_args: Vec<String>,
@@ -1218,15 +1195,6 @@ pub fn stream_cargo(
     cargo.arg("--message-format").arg("json")
          .stdout(Stdio::piped());
 
-    if stderr_isatty() && builder.ci_env == CiEnv::None &&
-        // if the terminal is reported as dumb, then we don't want to enable color for rustc
-        env::var_os("TERM").map(|t| t != *"dumb").unwrap_or(true) {
-        // since we pass message-format=json to cargo, we need to tell the rustc
-        // wrapper to give us colored output if necessary. This is because we
-        // only want Cargo's JSON output, not rustcs.
-        cargo.env("RUSTC_COLOR", "1");
-    }
-
     for arg in tail_args {
         cargo.arg(arg);
     }

src/doc/rustdoc/src/documentation-tests.md

@@ -323,6 +323,22 @@ compiles, then the test will fail. However please note that code failing
 with the current Rust release may work in a future release, as new features
 are added.
 
+```text
+/// Only runs on the 2018 edition.
+///
+/// ```edition2018
+/// let result: Result<i32, ParseIntError> = try {
+///     "1".parse::<i32>()?
+///         + "2".parse::<i32>()?
+///         + "3".parse::<i32>()?
+/// };
+/// ```
+```
+
+`edition2018` tells `rustdoc` that the code sample should be compiled the 2018
+edition of Rust. Similarly, you can specify `edition2015` to compile the code
+with the 2015 edition.
+
 ## Syntax reference
 
 The *exact* syntax for code blocks, including the edge cases, can be found

src/doc/unstable-book/src/language-features/try-blocks.md

@@ -9,9 +9,7 @@ The tracking issue for this feature is: [#31436]
 The `try_blocks` feature adds support for `try` blocks. A `try`
 block creates a new scope one can use the `?` operator in.
 
-```rust,ignore
-// This code needs the 2018 edition
-
+```rust,edition2018
 #![feature(try_blocks)]
 
 use std::num::ParseIntError;

src/libcore/slice/mod.rs

@@ -119,7 +119,7 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn first(&self) -> Option<&T> {
-        if self.is_empty() { None } else { Some(&self[0]) }
+        self.get(0)
     }
 
     /// Returns a mutable pointer to the first element of the slice, or `None` if it is empty.
@@ -137,7 +137,7 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn first_mut(&mut self) -> Option<&mut T> {
-        if self.is_empty() { None } else { Some(&mut self[0]) }
+        self.get_mut(0)
     }
 
     /// Returns the first and all the rest of the elements of the slice, or `None` if it is empty.
@@ -239,7 +239,8 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn last(&self) -> Option<&T> {
-        if self.is_empty() { None } else { Some(&self[self.len() - 1]) }
+        let last_idx = self.len().checked_sub(1)?;
+        self.get(last_idx)
     }
 
     /// Returns a mutable pointer to the last item in the slice.
@@ -257,9 +258,8 @@ impl<T> [T] {
     #[stable(feature = "rust1", since = "1.0.0")]
     #[inline]
     pub fn last_mut(&mut self) -> Option<&mut T> {
-        let len = self.len();
-        if len == 0 { return None; }
-        Some(&mut self[len - 1])
+        let last_idx = self.len().checked_sub(1)?;
+        self.get_mut(last_idx)
     }
 
     /// Returns a reference to an element or subslice depending on the type of
@@ -1618,6 +1618,63 @@ impl<T> [T] {
         }
     }
 
+    /// Copies elements from one part of the slice to another part of itself,
+    /// using a memmove.
+    ///
+    /// `src` is the range within `self` to copy from. `dest` is the starting
+    /// index of the range within `self` to copy to, which will have the same
+    /// length as `src`. The two ranges may overlap. The ends of the two ranges
+    /// must be less than or equal to `self.len()`.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic if either range exceeds the end of the slice,
+    /// or if the end of `src` is before the start.
+    ///
+    /// # Examples
+    ///
+    /// Copying four bytes within a slice:
+    ///
+    /// ```
+    /// # #![feature(copy_within)]
+    /// let mut bytes = *b"Hello, World!";
+    ///
+    /// bytes.copy_within(1..5, 8);
+    ///
+    /// assert_eq!(&bytes, b"Hello, Wello!");
+    /// ```
+    #[unstable(feature = "copy_within", issue = "54236")]
+    pub fn copy_within<R: ops::RangeBounds<usize>>(&mut self, src: R, dest: usize)
+    where
+        T: Copy,
+    {
+        let src_start = match src.start_bound() {
+            ops::Bound::Included(&n) => n,
+            ops::Bound::Excluded(&n) => n
+                .checked_add(1)
+                .unwrap_or_else(|| slice_index_overflow_fail()),
+            ops::Bound::Unbounded => 0,
+        };
+        let src_end = match src.end_bound() {
+            ops::Bound::Included(&n) => n
+                .checked_add(1)
+                .unwrap_or_else(|| slice_index_overflow_fail()),
+            ops::Bound::Excluded(&n) => n,
+            ops::Bound::Unbounded => self.len(),
+        };
+        assert!(src_start <= src_end, "src end is before src start");
+        assert!(src_end <= self.len(), "src is out of bounds");
+        let count = src_end - src_start;
+        assert!(dest <= self.len() - count, "dest is out of bounds");
+        unsafe {
+            ptr::copy(
+                self.get_unchecked(src_start),
+                self.get_unchecked_mut(dest),
+                count,
+            );
+        }
+    }
+
     /// Swaps all elements in `self` with those in `other`.
     ///
     /// The length of `other` must be the same as `self`.